542
FXUS63 KDMX 031032
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
532 AM CDT Wed Jun 3 2026

 ...Updated for the 12z Aviation Discussion...

.KEY MESSAGES...

- Dry conditions continue through Today, with winds increasing out
  the south.

- Marginal Risk (level 1 out of 5) of severe weather for this
  evening and Thursday afternoon/evening.

- Rain/storm chances continue into Friday evening with the
  possibility of severe weather and heavy rain.

- Temperatures return to the upper 80`s over the weekend.

&&

.SHORT TERM /THROUGH THURSDAY/...
Issued at 218 AM CDT Wed Jun 3 2026

Clear skies were present on Tuesday and the same will continue for
Today. High pressure that has been positioned over the Great Lakes
will continue to keep us clear and dry Today.

The high pressure will eventually drift to the south. As the high
drifts away, winds will eventually  shift from the east southeast to
more of a south wind. A tighter surface pressure gradient will begin
to work into NW Iowa increasing our winds later this afternoon. The
overall air profile will remain quite dry allowing for daytime deep
mixing to occur. Wind gusts could reach up to 30 mph due to the
deeper mixing. Due to the change in winds out of the south,
temperatures and dew points will be on the rise which will lead to a
more unstable airmass that will work into NW/Western Iowa. An
incoming cold front will trigger showers and storms in central
Nebraska and central South Dakota this afternoon. The storms will
possibility continue to push eastward but will struggle to
maintain their strength due to limited forcing and weak
instability as they reach Iowa later tonight. Showers and storms
look to stick around through Thursday afternoon, though not a
complete wash out, rain chances will continue into the
afternoon.

As we head into Thursday afternoon/evening hours, better instability
looks to work into Northwest Iowa and parts of Central Iowa, which
could lead to a few strong to severe storms. There is still
uncertainly on how well we can destabilize from the morning
convection, but if we can get clearing MUCAPE values could climb to
over 1000+ J/kg which will be enough to support strong to severe
storms. However, one factor that could limit organized severe
convection is the marginal amount of deep layer shear. Guidance is
hinting that deep layer shear will range from 25 to 35 kts. Due to
the low amount of deep layer shear and decent instability, the Storm
Prediction Center has placed NW Iowa and parts of Central Iowa in a
marginal risk (level 1 of 5) with the primary concerns being
damaging winds and large hail. These storms will have an ample
amount of moisture to work with as PWAT`s  ranging from 1.5 to 1.6
which is near the 90th percentile of PWAT climatology for early
June. This means that storms will be able to produce heavy rainfall
which could lead to isolated localized flash flooding in a few
spots. The Weather Prediction Center has placed NW and parts of
Central Iowa in a marginal risk for excessive rainfall to highlight
that risk.

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
Issued at 247 PM CDT Tue Jun 2 2026

The 500 mb ridge responsible for our dry mid-week conditions
will be suppressed south and eastward by Thursday night,
transitioning the upper level pattern over Iowa to more of a
southwest to zonal flow pattern. This pattern will have keep
persistent moisture advection up into the state Thursday night
into Friday, leading to additional scattered shower and storm
chances overnight. By Friday afternoon and evening, a shortwave
will drop southeastward into Iowa, bringing additional synoptic
forcing and a cool front. Showers and storms will develop along
this boundary within a moist and unstable environment. Wind
shear on Friday will once again be on the lower end, but with
the boundary passage and upper level support, certainly can`t
rule out more strong to severe storms late Friday into the
evening. Likewise, a high PWAT environment (1.6 to 1.7") will
still be in place ahead of this boundary, resulting in another
round of efficient and potentially widespread rainfall. Again,
our dry spell should allow us to handle most of this, but rain
falling in similar areas over multiple days could lead to some
localized hydro concerns into the weekend.

Through Saturday and Sunday, a brief period of upper level
ridging will bring warmer and somewhat drier conditions over
Iowa, although shower and storm chances could still linger over
the southern portions of the area. This reprieve looks fairly
brief, as Sunday night into the beginning of next week could see
another wet pattern develop.

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 532 AM CDT Wed Jun 3 2026

VFR conditions will prevail at most terminals through the end of
this TAF period. Skies are mostly clear this morning with winds
out of the ESE under 10 kts. Over the next several hours, winds
will shift to more of a south wind and will increase to 12-15
kts with gusts reaching up to 20 kts. Skies will be mostly
clear the rest of the day today. Closer to 4Z Thursday, clouds
will begin to increase ahead of a cold front. Showers and storms
could move into MCW and FOD closer to the end of this TAF
period but confidence is low to issue prob30s due to timing and
coverage uncertainty.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

SHORT TERM...TDR
LONG TERM...Dodson
AVIATION...TDR/Ansorge